Office of Academic Affairs
Indian Institute of Science Education and Research Bhopal

Earth and Environmental Sciences

EES 302: Igneous Petrology (3)

Prerequisites (Desirable): EES 301

Learning Objectives:

This is an introductory course to provide a basic understanding of the different groups of igneous rocks and the processes involved in their formation. This course starts with the chemistry and physics of melts and their behavior under varying temperature and pressure conditions, and goes on to discuss the different kinds of igneous rocks and rock suites that form under different tectonic conditions. The generation of primary basalts at mid-ocean ridges and hotspots, and the generation of all other igneous rocks (ranging from acidic to ultrabasic) from primary basalts is discussed. Upon completion of this course the student will have a comprehensive understanding of the mechanisms which control the diversity of igneous rocks and their relationships with tectonic regimes.

Course Contents:

Some Fundamental Concepts:
Introduction; The Earth’s interior; Origin of the Solar System and differentiation of Earth; Meteorites; P-T variations with depth; Review of mineralogy.

Classification of Igneous Rocks:
Compositional terms; IUGS classification; Aphanitic and pyroclastic rocks; Primary textures and crystal melt interactions; Secondary textures and post-magmatic changes; Igneous textural terms; Extrusive processes, products and landforms; Intrusive processes and bodies; Hydrothermal Systems.

Phase Rule and Various Igneous Systems:
Revision of thermodynamics; Melting behavior of magmas; Phase equilibrium and phase rule; Application of the phase rule to the H2O system; One component systems; Binary systems; Ternary systems; Systems with more than three components; Reaction series; Effect of pressure on melting behavior; Effect of fluids on melting behavior.

Chemical Petrology:
Major and minor elements in the crust; Analytical methods and results; Normative minerals; Variation diagrams using major and minor elements; Using variation diagram to model magmatic evolution; Trace element distribution; Batch melting and Rayleigh fractionation; Rare Earth Elements; Spider diagrams; Applications of trace elements to igneous systems; Geochemical criterion for distinguishing between tectonic environments; Isotopes and their applications to igneous processes.

Generation of Basaltic Magmas and their Diversification:
Petrology of the mantle; Mantle melting; Generation of basalts from a chemically uniform mantle; Primary magmas; A chemically heterogeneous mantle model; Partial melting; Magma differentiation; Magma mixing; Assimilation; Boundary layers, in-situ crystallization, and compositional convection; Tectonic-igneous association.

Layered Mafic Intrusions:
Igneous layering; Examples of layered mafic intrusions; Processes of crystallization, differentiation and layering in these complexes.

Mid-Ocean Ridge Volcanism:
Volcanism at constructive plate boundaries; Mid-ocean Ridge Basalts (MoRB); Structure of the oceanic crust and upper mantle; MORB chemistry; Petrogenesis of MORB.

Continental Flood Basalts (CFB) and Oceanic Island Basalts (OIB):
Tectonic setting for CFBs; Classical examples of CFBs, chemistry and petrogenesis of CFBs; Oceanic intraplate volcanic activities; Types of OIB magmas; Chemistry and petrogenesis of OIBs.

Subduction Related Igneous Activity:
Island arc volcanism, rocks suites, and magma series; Chemistry of island arcs; Spatial and temporal variations in island arcs; Petrography and petrogenesis of island arc magmas; Continental arcs; Classical examples of continental arcs; Chemistry and petrogenesis of continental arc magmas.

Continental Alkaline Magmatism:
Continental rift-associated alkaline magmatism; Carbonatites; Highly potassic rocks; Mantle metasomatism and mantle xenoliths.

Granitoids and Anorthosites:
Petrography, chemistry and petrogenesis of granitiods; Granitoid classification; Chemical discrimination of tectonic granitoids; Origin of the continental crust; Archaean anorthosites; Proterozoic anorthosites; Lunar anorthosites.

Suggested Readings :

  1. Winter, J. D., 2009, An introduction to Igneous and Metamorphic Petrology (2nd Edition), Prentice Hall.
  2. Philpotts, A., and Auge, J., 2009, Princples of Igneous and Metamorphic Petrology (2nd Edition) Cambridge University Press.
  3. Carmichael, I., Turner, F., and Verhoogen, F., 1974, Igneous Petrology, McGraw Hill Publications.

Previous Back to Course List Next